Antarctica, corals … five climatic hotspots could be overcome with the current level of warming

Antarctica, corals … five climatic hotspots could be overcome with the current level of warming

Antarctica, corals … five climatic hotspots could be overcome with the current level of warming

Sermeq Glacier, Greenland, September 11, 2021.

This is undoubtedly the most frightening notion in the entire repertoire of disasters conveyed by the climate crisis: that of points of no return (points of no return, in English), these warming thresholds beyond which parts of the climate system enter a completely new and often irreversible state, with major impacts on the climate, ecosystems and human societies.

In the most updated assessment on the matter, published on Friday 9 September a Sciencean international team of researchers recognized for their expertise in the climate identifies sixteen breaking points that lead to a global or regional escape. They show the risk of multiplying these tipping points beyond 1.5 ° C warming compared to the pre-industrial era – the most ambitious goal of the Paris climate agreement – with a threat increasing with every tenth of a degree more .

Read also: The summer of 2022 was the hottest ever recorded in Europe, according to the European Copernicus program

But even at current levels of warming (+ 1.1 ° C), the world risks exceeding five of these dangerous thresholds, scientists warn: the disappearance of the Greenland and West Antarctic ice sheets, the steep thaw of permafrost ( permanently frozen ground) in the boreal regions, the extinction of tropical and subtropical corals and the cessation of an important element of ocean circulation in the North Atlantic.

The topic has been the subject of growing concern from scientists and the general public since an initial global assessment in 2008. The Intergovernmental Panel on Climate Change (IPCC) first addressed this notion in its report on the ‘August 2021, indicating that the risk of triggering tipping points has become high at 2 ° C of warming and very high between 2.5 ° C and 4 ° C. But he hadn’t undertaken a systematic evaluation. The new study, based on an analysis of 200 scientific publications, climate models, observations and paleoclimatic data, aims to be more comprehensive, often proving more alarming.

“Self-sufficient system”

The researchers concluded that sixteen major biophysical systems involved in regulating Earth’s climate – up from nine in the 2008 assessment – have the potential to cross turning points, where change is self-perpetuating. In other words, if these systems – such as the ice sheet, the ocean or the rainforest – crossed these thresholds, they would continue to evolve into a new state, even if the global temperature stopped rising. This change is, according to their definition, most of the time irreversible, but not necessarily abrupt as the duration of the transition varies from a few decades to centuries or millennia.

You still have 66.02% of this article to read. The following is for subscribers only.

Leave a Reply

Your email address will not be published.